dynami, also known as chaos theory, and we use that theory to structure equations that calculate the energy flow through our ecosystem from plants, say, to herbivores to carnivores. it's important to understand the effects of species on one another because that is changing quite a bit these days. many species are going extinct due to human activity, and also new species are invading ecosystems due to human activity. ecosystems form much more tightly connected networks than many other networks. what happens is that each species is typically within three links of all other species within the ecosystem. that's a lot closer than, say, the six degrees of separation that is supposed to separate human's familiarity networks, "who knows who" within, say, the u.s. and so these are tight networks where effects on one species can propagate to many other species quite quickly. one of the most famous examples of the effects of one species on the others within the ecosystem through the network that we've been studying is the sea otter example. back in the 1800s, the russians and several other western cou